Jessen, R. R., R. N. Gwinn, and J. L. K0prowski. 2013. Sciurillus pusillus (Rodentia: Sciuridae). Mammalian Species 49:75-79.

Sciurillus pusillus (E. Geoffroy Saint-Hilaire, 1803) is a sciurid commonly called the Neotropical pygmy squirrel. S. pusillus is an exceptionally small species of tree squirrel that appears pale gray due to a grizzled pattern of light hair tips on the dorsal pelage. Ranging from Amazonian Peru and Brazil northeast to the Guianas with a patchy distribution, S. pusillus is a denizen of the upper canopy of lowland rain forest. This species is listed as ‘‘Data Deficient’’ by the International Union for Conservation of Nature and Natural Resources.